Reply #45: A girder on Floor 13 ...

[Bassman66]

From the MIST report This is very specific:

"Eventually, a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories."

The evidence for this event is?

Am I right in thinking this is all subjective?